The present invention relates generally to fiber-optic inspection systems, and more specifically to a microscope for inspecting fiber-optic endfaces in multi-fiber connectors.
The proliferation of fiber-optic communications has lead to its wide spread implementation and use in industry. As a result, fiber-based communication systems have progressed toward utilizing multi-fiber connectors, such as fiber-optic ribbon connectors, for high density interconnects, rather than using electrical copper connectors as in the past. The increased use of these multi-fiber connectors, particularly in backplanes or in other situations in which the connectors are recessed and difficult to access, has created a need for a system that can adequately inspect the optical fibers while the connectors are still mounted.
It is well known in the industry that the endfaces of optical fibers must be kept clean and undamaged within fiber-optic communication systems. A fiber-optic endface is the cross-sectional surface that is created when an optical fiber is cut for termination. Failure to keep such endfaces clean and undamaged results in signal loss because of scattering effects at the endface of the optical fiber. As bandwidths increase, particularly with the rise of wavelength division multiplexing (WDM) technology, the need for cleanliness at the fiber-optic endface is even more important. Further, since fiber-optic communication systems handle heavy bandwidth traffic, the cleanliness at the fiber-optic endface is particularly important because the laser power driving the fiber-optic communication signals is typically higher. When a high-powered laser strikes a small piece of debris on the fiber-optic endface, the debris burns leaving a film of soot on the fiber-optic endface that degrades communication signals. As a result, the xe2x80x9cdirtyxe2x80x9d fiber-optic endface at the interconnect point must be taken out of service and repaired.
However, backplane interconnects that accept fiber-optic arrays and communication system devices are notoriously difficult to access for maintenance, cleaning and repair. When a particular multi-fiber connector in a backplane needs service, a technician typically removes a module from a slot in a rack-mount system. A module is typically a printed circuit board, or xe2x80x9cdaughter card,xe2x80x9d that interfaces with a backplane in the rack-mount system when xe2x80x9cplugged in.xe2x80x9d The technician then needs to inspect and clean the multi-fiber connectors located at the back of the empty slot from where the module was removed. A typical slot is 1.5 inches wide and 12 inches deep and rather difficult to access for service. Other than removing the multi-fiber connector from the backplane altogether, another way to view and clean the fiber-optic endfaces in the connector is to use a video microscope. Obviously, because of the narrow and deep nature of the empty slot, most microscopes are not manufactured to be used in this situation.
Some microscope manufacturers have designed xe2x80x9clong reachxe2x80x9d video microscopes to reach back into this cavity for visual rendering and cleaning purposes. However, these microscopes are unable to precisely locate and focus upon each fiber-optic endface situated within the multi-fiber connector. Because each and every fiber-optic endface needs to be inspected, it is essential to have a microscope capable of focusing upon each individual fiber-optic endface in the ribbon connector. Current long reach microscopes tend to xe2x80x9cjumpxe2x80x9d quickly across the multi-fiber connector which holds the fiber-optic endfaces in a linear array. Consequently, these microscopes tend to skip over some fiber-optic endfaces. Furthermore, at high magnification it is very difficult to control the speed at which these microscopes pan across the multi-fiber connector. Thus, it cannot be assured that each and every fiber-optic endface has been focused upon and inspected properly.
Therefore, a need exists for a microscope capable of focusing upon each fiber-optic endface situated within a recessed multi-fiber connector.
In accordance with this invention a microscope for inspecting the endfaces of each optical fiber in a multi-fiber connector is provided.
The microscope comprises a tip, a slider assembly, a slider chassis and a cam assembly. The tip is designed to interface with a multi-fiber connector and is connected to the slider assembly. The slider assembly is in turn engaged with the slider chassis which constrains the movement of the slider assembly along an axis of motion. The cam assembly interfaces with the slider assembly and is capable of translating the slider assembly along its constrained axis of motion. By providing a means for controlling motion of the slider assembly back and forth, each fiber-optic endface in a multi-fiber connector can be located and inspected more precisely.
In accordance with further aspects of the present invention, the cam assembly includes a cam, a cam shaft and a cam tip. The cam tip is designed to interface with a groove in the backend of the slider assembly. The cam assembly is capable of being rotated by remote means, such as by a fine adjustment knob. The rotation of cam assembly and specifically the cam tip causes the translation of the slide assembly along its constrained axis of motion. In particular, when rotated the cam tip applies force to the groove of the slider assembly which in turn causes the translation of the slider assembly.
In accordance with yet further aspects of the present invention, in another embodiment, the microscope includes an optical imaging axis and a tip through which this optical imaging axis extends. As in the embodiments described above, the tip is designed to interface with a recessed multi-fiber connector. The tip of this embodiment also includes a set of surfaces for re-directing the optical imaging axis such that it is orthogonal to each of the fiber-optic endfaces of a multi-fiber connector. These surfaces preferably consist of two reflecting surfaces.